Electric reciprocating motor



June 30, 1942.

T. J. MURPHY ELECTRIC REC IPROCATIING MOTOR Filed Jan. 11, 1939 2Sheets-Sheet 1 ATTORN EYS.

J1me 1942- T. J. MURPHY ELECTRIC RECIPROCATING MOTOR Filed Jan. 11, 19392 Sheets-Sheet 2 Winn INVENTOR ATTORNEYS,

u msuurlan/gq Patented June 30, 1942 UNITED STATES PATENT OFFICEELECTRIC RECIPROCATIN G MOTOR Thomas J. Murphy, Stamford, Conn.

Application January 11, 1939, Serial No. 250,349

15 Claims.

This invention relates to dry shaving devices, and more particularly toan actuator or motor for operating the movable cutting member. Althoughit is shown by way of example as applied to a dry shaving deviceinvolving a movable cutter it may of course be applied to the operationof other devices where there is a reciprocating element.

This application is a continuation in part of my prior applicationSerial No. 754,812, filed November 26, 1934 for Dry shaving device, andwhich issued as Patent Number 2,146,643 on February 7, 1939.

It is an object of the invention to provide an actuator operated byalternating electrical current which is simple in construction andoperates without any make or break devices so that there is no arcing orsparking to interfere with radios and similar devices. It will operatewith a minimum of noise and there areno points or similar contacts toburn out.

It is also an object to provide such an actuator which may be easily andeffectively mounted within the handle employed for dry shaving andsimilar devices.

With the foregoing and other objects in view I have devised an improvedconstruction as illustrated in the accompanying drawings forming a partof this application. It is, however, to be understood that I am notlimited to the specific details shown but may employ various changes andmodifications within the scope of the invention.

In these drawings:

Fig. 1 is a side elevation of my improved actuator as applied to a dryshaving device, a portion of one side of the enclosing casing beingremoved to more clearly show the construction;

Fig. 2 is a similar view looking from the right of Fig. 1 showing oneside of the casing and certain elements in section;

Fig. 3 is a top plan view and partial section, the section beingsubstantially on line 3-3 of Fig. 1;

Fig. 4 is a side elevation on an enlarged scale with one-half the casingremoved and certain parts in section to more clearly show theconstruction;

Fig. 5 is a similar view looking from the right of Fig. 6 showing thecasing in section but the interior mechanism in elevation;

Fig. 6 is a detailed partial side elevation and partial section of aportion of the assembly of th operating mechanism immediately below thecutter head;

Fig. 7 is a wiring diagram for one arrangement of the actuator;

Figs. 8, 9, 10 and 11 are similar diagrams of modified arrangements;

Fig. 12 is a side elevation showing a modified arrangement of the core;

Figs. 13 and 14 are side and edge views respectively of anotherarrangement of the core;

Fig. 15 is a partial section and partial elevation of the operativeconnecting means between the actuator and the cutter head or otherelement to be operated;

Fig. 16 is a side elevation of the upper end portion looking from theleft of Fig. 15;

Fig. 17 is a top plan view thereof;

Fig. 18 is a partial side elevation and partial section of a connectingcontact;

Fig. 19 is an end view thereof;

Fig. 20 is a detail section of a portion of the casing substantially online 20-40 of Fig. 1;

Fig. 21 is a similar section substantially on line 2|--2l of Fig. 1;

Fig. 22 is a side elevation of the mounting yoke for the armature;

Fig. 23 is an edge view thereof;

Fig. 24 is a top view thereof;

Fig. 25 is a side elevation of a spring support used in the actuator;

Fig. 26 is an edge view looking from the right of Fig. 25;

Fig. 27 is a top plan view of the member of Figs. 25 and 26; and

Fig. 28 is a longitudinal section of an improved means for connectingthis device to an outlet for source of power.

The device comprises a casing I made in two sections 2 and 3, preferablyof some molded insulating material such for example as Bakelite orsimilar synthetic resins, or rubber composition, which casing carries atone end a cutter head 4 and encloses the operating mechanism for themovable element of this cutter head indicated at 5. The connections forthis operating mechanism to a source of electrical operating current areat the lower end of this casing, or that is, at the opposite end fromthe cutter head 4.

This cutter head may be of difierent constructions. That shown comprisesa substantially rectangular body including mounting blocks 6 to theopposite sides of which are secured plates I having inwardly extendingupper edges 8 on which are transversely extending stationary guard andcutter teeth substantially as shown in the application above mentioned.The longitudinally reciprocating cutter 5 is mounted between the sidemembers 1 and has transversely extending cutter teeth 9 at the innersides of the teeth [to cooperate therewith for the shaving operation.Both sets of cutter teeth are in spaced relation or separated by alongitudinal slot "I in which is mounted a stationary comb or guard H toprevent entrance of the skin between the two sets of cutter teeth. Thusthere is a cuttingdevice on each side of the slot and each comprises aseries of guard teeth and a seriessof cutting teeth cooperatingtherewith arranged with the devices opposed and facing each other. Thefree ends of the teeth of the two devices extend toward each other butare separated by the longitudinal slot It the same as shown in the priorapplication. This cutter head may be mounted in the casing by anysuitable means such for example as screws I2. It will of course beunderstood that in using the device as a dry shaver the outer edge orsurface of the head is moved back and forth over the surface of the skinfor the shaving operation. Also, it will be understood that thisactuatoris not limited to use with this particular construc tion ofdevice.

To secure the cutting effect it is necessary that the cutter bereciprocated in a direction longitudinally of the slot III, or that is,transversely of the guard teeth 3 and immediately back of the guardteeth for the proper shearing effect. The teeth of the movable cutter 5are held against the back of the stationary teeth 8 by a spring |3pressing the operating pin l4 against the movable cutter 5. Thismaintains the proper pressure between the teeth and automatically takesup wear. This pin is rounded at its upper end as indicated at l5 to seatin a recess in the lower side of the cutter 5 as shown in Figs. 1 and 4,the rounded end permitting a certain amount of rocking movement withoutbinding. The end of the pin is also preferably flattened on its oppositesides as indicated at It in a plane extending in the general directionof the reciprocal movement to still further reduce the danger ofbinding.

The actuator for operating the movable cutterv comprises a laminatedcore l1 made up of a series of plates of magnetic material such as softiron placed side by side to form a core or poles of the desiredthickness and'prevent heating. This core has three magnetic poles orlegs, the two outer poles l3 and I9 and the central leg or pole 20. Thewindings indicated generally at 2| for magnetizing the poles are mountedon the outer poles l8 and I9. Various arrangements of these windings maybe used several examples of which are shown in Figs. '1 to 11 which willbe described more specifically presently. At the lower or free ends ofthese poles is an oscillating armature 22 of magnetic material whichbridges the spaces means maybe employed for securing the free betweenthe poles and is spaced a short distance preferably having a transversegroove in whichthis member 25 is seated so as to properly posi-- tionthe armature and retain it in the proper location. The armature may besecured to the member 25 by any suitable means such as one or morescrews 26 each of which is held against loosening up by a lock nut orwasher 21. Various ends of the member 25 to the arms of the member 24.In the present case they are seated with in the channel of the member 24and secured in proper location to give the proper spacing of thearmature 22 from the ends of the poles |8, it and 2|) by means ofassembling screws 28. Holes 29 may also be provided in the arms of themember 24 to permit entrance of solder into the surfaces between themembers 24 and 25, and after the joint has been properly soldered theassembling screws 28 may be removed. This makes a very strong and rigidconnection which will maintain the proper relation between the elementsindefinitely. If preferred the members 24 and 25 may be made in onepiece with the joint at the top passing through the center hole for pin38.

At its upper end the member 24 is mounted on a cross bar 30 of aninverted substantially U shaped spring member or support 3|. Theelements of this member are shown as being substantially flat orrectangular in cross section with the upper cross bar 30 seated withinthe channel shaped cross member 32 of the member 24. A bar 33 is placedon the lower side of the cross member 30, and. attaching screws 34 passthrough the portion 32 and portion 3|! and are threaded into the bar 33to secure the members together as shown more clearly in Fig. 6. Thelower free ends of the side members 35 of the spring support 3| aresecured to the sides of the center pole 20 of the magnetic core by anysuitable means such as the rivets 36 extending transversely through thiscore. These arms are also turnedthrough an angle of about at theintermediate portions 31 so that they can flex in a plane at rightangles to these flat portions as the armature 22 reciprocates. armature22 reclprocates back and forth toward and from the poles I8 and I9 thismotion is transmitted by the yoke or support 23 to the spring support3|, causing the upper portion thereof, including the cross bar 30, toreciprocate back and forth flexing the spring arms 31 as the poles I8and I! are magnetized in a manner as will presently be described. Theydraw the armature 22 alternately to the right and left as viewed inFigs. 1, 4 and '7 to 11 inclusive, while the spring 3| tends to bring itback and retain it in the intermediate or substantially centralposition.

This upper portion 32 is connected to the cutter member 5 to oscillatethe same longitudinally of the head by means of an oscillating assemblycomprising a pin 38 extending through the member 32 and threaded intothe bar 33 as shown in Fig. 12. This pin has a flange 39 between whichand the' top of the bar 32 is clamped a flat spring 40. This springextends laterally from opposite sides of the bar 32 as shown in Fig. 4and has downwardly and inwardly extending portions 4| resting on the topof core IT. This supplemental spring 40 is preferably made from flatstock about of an inch wide and augments the spring support 3|. I havefound it difficult in practice to make the fulcrum spring support 3|stiff enough and still have it operate without breaking after a while.If this stock were made sufficiently heavy it interfered with the properworking and there was considerable breakage but with the auxiliaryspring 40 the spring support 3| may be reduced in thickness to about.020". The auxiliary spring 40 greatly reduces the stresses on thespring 3|. It also assists in lining up the armature 22 more readilywith That is, as the the tips of the pole pieces l3, l3 and 20. Theoperating pin or stud I4 is mounted to slide on the stud 38, and coilspring l3 between the flange 39 on pin 33 and the flange 42 on the pinl4 tends to shift the pin |4 outwardly and holds its tapered and roundedupper end portion l5 seated in the recess or bearing in the bottom 43 ofthe oscillating cutter 5. This maintains a close connection between theoperating pin and the reciprocating cutter member, automatically takingup wear and preventing the development of looseness and lost motion. Asindicated above the opposite sides of the tapered end I5 are preferablyflattened somewhat as indicated at ii to give free rocking movement ofthe end of the pin in its bearing in the cutter and prevent cramping orbinding. Spring i 3 also holds the teeth of cutter 5 against the guardteeth 3.

With this mounting of the armature 22 and the yoke 23 and spring support3|, as the work on the cutter increases the ratio of leverage increasesproportionately, that is, the effective fulcrum on or point of bendingin the flat spring portions 31 moves up and so decreases the liabilityof stalling. In fact it could never stall the armature, for withsufiicient load the movement of the cutter could come practically tozero as the fulcrum has moved up to it so that the cutter teeth wouldnot be broken. Also, as the leverage increases the movement of thecutter decreases, but the power on the cutter increases so that it cancut through heavier hairs.

Several arrangements of the coils for energizing the poles l3, l8 and 20for oscillating the armature 22 are indicated diagrammatically in Figs.7 to 11. I am not, however, limited to these specific arrangements asother arrangements are possible. It will be seen the three connectedlegs or pole portions l3, l9 and 20 form two magnetic circuits, onecircuit being through the legs l3 and 20, the connecting end portion 44and the armature 22 with the intermediate air gaps. While the othermagnetic circuit or path iS legs I9, 20, the connecting portion 45 andthe armature 22 with the air gaps between the armature and the poles l9and 20. The poles are magnetized in such a way so as to reciprocate oroscillate armature 22 by a combination of alternating and direct currentcoils on the legs, preferably the outer legs l8 and I9.

In the arrangement shown in Fig, 7 there is a pair of alternatingcurrent working coils 45 and 41 one on each leg l8 and i9 and connectedin series by the lead 48. Coil 43 is connected by lead 49 with one sideof a source of alternating current supply 50. Mounted on the legs I8 andI9 are also two sets of direct current exciter coils 5| and 52, and 53and 54, coils 5| and 52 being connected in series by a lead 55 and thecoils 53 and 54 being connected in series by a lead 56. The oppositeends of the coils 52 and 54 are connected by the lead 51 to thealternating current coil 41, while the other end of the coil 5| isconnected by a lead 53 with the outlet connection of a rectifier 59. Theother end of the coil 53 is connected by lead 53 to the inlet of asecond rectifier 6|. The inlet of the rectifier 59 and the outlet fromthe rectifier 6| are connected to the other side 62 of the source ofalternating current 50. It will be seen the coils 46 and 41 are wound inthe same sense, while the coils 5| and 52 are wound in the oppositesense, and coils 53 and 54 are wound in the opposite sense.

If now we assume that during one half of the alternating current cyclecurrent enters through the lead 49 it will pass through the coils and41, lead 51, coils 54 and 53, and through the rectifier 6| to the otherside62 of the alternating current supply. Thus if the pole I3 is southpole I9 is also south and central pole 20 is north. However, as the coil54 is wound in the opposite sense to the coil 41 it will tend tosuppress the efi'ectof coil 41 or cancel it out, while as coil 53 iswound in the same sense as the coil 46 its effect will be added to thatof coil 43 and the magnetization of the leg l3 will be increased, whilethe magnetization of the leg or pole I! will be decreased or cancelledand there will be a strong force tending to pull the armature 22 to theright or toward the pole I3. During the other half of the cycle currententers through the lead 62, passes through' the rectifier 59 to thecoils 5| and 52, by lead 51 to coils 41 and 46, and then by lead 49 tothe other side of the A. C. supply 50. At this time as the coils 52 and41 are wound in the same sense they will assist each other and theireffect will be added up on the pole l9, while on the other hand coil 5|is wound in the opposite sense to coil 46 and therefore they will opposeeach other thus reducing the magnetization of the pole Hi to practicallyzero. This will cause heavy pull on the armature 22 to the left ortoward the pole I9. Thus the two poles l8 and I9 will be alternatelmagnetized to the maximum extent by the combination of an A. C. and a D.C. coil wound in the same sense while themagnetization of the other poleis reduced to a minimum by operation of an A. C. and D. C. coil actingin opposition to each other. Thus a maximum pull is imparted to thearmature 22 alternately in opposite directions reciprocating thisarmature back and forth in synchronism with the A. C. supply, and thismotion is transmitted to the movable inner cutter 5 through thesupporting yoke 23, spring support 3| and the operating pin l4,

While the armature is being drawn toward either pole is or l9 it fiexesthe spring support 3| and also the auxiliary spring 40, and thereforethese springs 3| and 40 tend to move the armature back to the central orintermediate position, and when the magnetization is reversed thesesprings move the armature backwardly during the first half of itsmovement in the opposite direction. It will be noted that with thisarrangement there is no making or breaking of the circuit such as wouldcause interference with radios or similar apparatus, and there is nospark gap or arcing. The actuator therefore actuates very quietly andeffectively with no interference with other apparatus. It is preferredto provide the auxiliary spring 40 with downwardly extending loops orreverse bends 63 in the top or horizontal portion of this spring onopposite sides of its connection to the yoke 23 which permit a certainamount of transverse flexing.

Figs. 8, 9, l0 and 11 show examples of modified arrangements for thecoils and their connections which may be used, but there are others. InFig. 10 the A. C. and D. C. coils are shown with light and heavy linesso that they may be more easily distinguished, but this showing is notintended to indicate that the wires of the different coils are heavier,although they may or may not be heavier as desired.

In Fig. 8 the two A. C. coils are indicated at 54 and 65 connected inseries by the intermediate lead 65, and the D. C. coils are indicated at51 and 68 connected in series by lead 69. The opposite end of the coil65 is connected by lead 49 with one side of the A. C. supply 56, whilethe other end of the coil 64 is connected intermediate the coils 61 and66 as indicated at 16. The other end of coil 61 is connected to theoutlet of the rectiher 59 while the other end of the coil 66 isconnected by the lead 1| to the inlet of the rectifier 6|, and as in theform of Fig. '7 the other side 62 of the A. C. supply 56 is connectedbetween the two rectifiers 59 and 6|, that is, to the inlet of rectifier59 and the outlet of rectifier 6|.

If now we assume that during one half of the cycle current entersthrough the lead 49, coils 65 and 64 will magnetize the two poles l6 andIS in the same sense as these two coils are wound in the same sense.However, current from the coil 64 flows through the coil 66 to therectifier 6| and out the lead 62 to the A. C. supply. As coil 68 iswound in the same sense as coil 65 its effect will build up or be addedto that of coil 65 and the pull of the pole |8 on the armature 22 willbe a great deal more than the pull of the pole i9 and the armature willtherefore move to the right. During the next half cycle current willenter through the lead 62, pass through the rectifier 59 to coil 61 andby connection 10 through the coils 64 and 65 to the other side 49 of theA. C. supply. During this time as the coils 61 and 64 are wound in thesame sense their effects will be built up or added so that the pole I9is magnetized to a much greater extent than the pole l6 and the armaturewill be drawn to the left or toward the pole l9.

In the arrangement of Fig. 9 the coils are the same as in Fig. 8 but theleads to the A. C. coils 64 and 65 are reversed. Thus the lead 49 fromone side of the A. C. supply is connected to the end of the coil 64which in the form of Fig. 8 is connected at 16 between the D. C. coils61 and 68. In the form of Fig. 9, however, this connection 10 betweenthe D. C. coils is connected to the other end of the coil 65 to whichthe lead 49 is connected in Fig. 8. Now if we assume in the arrangementof Fig. 9 current is entering during one-half of the A. C. cycle throughthe lead 49 it will pass through the A. C. coils 64 and 65 to theconnection 10, to the D. C. coil 66, and the rectifier 6| to the lead 62at the other side of the A. C. supply 50. As the coils 64 and 65 arewound in the same sense they will magnetize the poles l9 and IS in thesame sense but now the coil 66 is wound in the opposite sense to thecoil 65 and therefore its effect instead of being added to or increasingthat of coil 65 is opposed to coil 65, reducing magnetization of pole I8to zero so that pole i9 acting on the armature 22 will draw it to theleft. During the other half of the cycle current enters through the lead62, passes through the rectifier 59 to the coil 61 through theconnection 10 to the coils 65 and 64 and out the lead 49. Coils 64 and65 energize the poles in the same sense, but in this case coil 61 isopposed to coil 64 and reduces or cancels out its effect so that theeffect of coil 65 is to energize the pole l8 and pull the armature tothe right.

In Fig. 10 the A. C. and D. C. coils are shown as wound together, one ontop of the other. The coils are connected the same as in Fig. 9 andtherefore the same reference numerals are employed to indicate thecoils.

In Fig. 11 the connections are reversed from that of Fig. 8, that is theconnection between the coils 65 and 64 indicated at 12, instead of beingfrom the lower end of coil 65 to the upper end of coil 64 as in Fig. 8,connects the two lower or adjacent ends of coils 65 and 64. The other orupper end of the coil 64 is connected by lead 19 to the connecting point16 between the two D. C. coils 61 and 66. The connection between thesetwo coils indicated at 14 is also reversed from that of Fig. 8, that is,instead of the upper ends of the coils 61 and 69 being connected as inFig. 8 the upper end of coil 61 is connected to the lower end of coil 69and the upper end of the coil 66 is connected by the lead 1| to therectifier 6|.

In the arrangement of the coils and connections as shown in Figs. 7 to10 the polarity of the center pole or leg 29 reverses in each cycle.Equally good results are obtained if the connections to the coils arereversed as indicated in Fig. 11 so that the polarity of the center leg26 does not reverse and thus is secured a practically constant D. C.pole of this middle leg. In fact it seems to require less turns of wirefor the same field strength with the latter arrangement. Thus as in thisarrangement the A. C. coils 64 and 65 add to each other or arecomplementary, and the D. C. coils 61 and 68 oppose each other, we getthis efi'ect. If we assume that during one half of the cycle currententers through the lead 49 it will pass through the coils 65 and 64 asindicated, and from the top of coil 64 to the connection 10 where it iscarried to the lower end of the coil 68, through this coil to therectifier 6|, and then by lead 62 to the other side of the supply. Inthis arrangement the coil 68 opposes the coil 65 leaving the leg I9 tobe energized by the coil 64. On the other half of the cycle currententers through the lead 62, passes through rectifier 59 and then throughcoil 61 to the connection 10, and then through the A. C. coils 64 and65. In this case the coil 61 opposes coil 64 and coil 65 energizes thepole l8, but the center pole 20 does not reverse thus giving apractically constant D. C. pole of this middle leg.

Very good results are secured by placing the exciter coils on the centerleg, but for mechanical reasons it is preferred in this specific deviceto leave the center leg free of winding. Other arrangements of thesecore legs may also be used. Thus for example as shown in Fig. 12 thecore can be arranged as two U-shaped members 15 each comprising alaminated structure and placed with a leg 16 of each side by side asshown to provide the center pole 20. The coil arrangements of either oneof Figs. 7 to 11 may be used on this core.

In Figs. 13 and 14 the two U-shaped laminated cores 15 are spacedlaterally from each other providing the poles |8a and |9a correspondingto the poles |8 and IQ of the other forms. The coil arrangements ofFigs, '7 to 11 may be used on the legs of this core to magnetize them inthe same manner, an A. C. and a D. C. coil being on one leg of each ofthe two cores 15.

In Figs. 1, 2, 4, 15, 18, 19 and 28 is shown a convenient means formounting the rectifiers 59 and 6|, connecting them to the actuatormounted in the casing and for connecting them or plugging into theoutlet from the A. C. supply, such as any outlet from the standard housecircuit. In this arrangement the rectifiers are mounted in an attachmentplug cap indicated at 11. This comprises a casing of insulated materialmade in two sections, only one of which is shown at 16, connected whenassembled by any suitable means such as transverse rivets or screws 19.The two rectifiers 59 and 6| are preferably formed by a rectox assemblycomprising a suitable number of copper plates side by side in contactand having on one surface a coating of copper oxide which, as is wellknown in tho. rectox elements, permits electric current to flow in onedirection but prevents it flowing in the opposite direction, thuscutting out one half of the cycle of alternating current. However, inthe present case I divide this rectifier assembly thus making in effecttwo rectifiers and there- 1 fore utilize the full alternating current.

As shown in Fig. 28 the rectifier assembly comprises a series of copperplates 89 having on one side the copper oxide coating 8I. Intermediatethis series of plates is placed a conductor plate 82 having extendingfrom one side thereof a blade contact 83 projecting from the casing. Onthe opposite side of the plates 89 is a plate 84 connecting to a lead 85and carried through a cable 86 to a female contact 81 in another plug 88having an insulating casing. On the other side of the other half of therectox plates is a contact plate 89 connected by a lead 90 to a similarcontact element 9| in the plug 88. The other projecting blade contact 92is a part of the contact plate 93 contacting a plate 94 which isseparated by an insulating plate 95 from the plate 89. However, as theplates 93 and 94 are in contact current can flow directly from thecontact finger 92 to the plate 94 which is connected by lead 98 in thecable 86 to a contact 91 in the plug 88. Plate 93 is preferably somewhatdished as shown so that when the elements are assembled on the crossbolt 98 this plate will yield or flatten as the elements of therectifier heat up under their rectifying action and thus expand. Thisspring action of the plate 93 main.- tains the parts in proper contact,but also permits the necessary expansion under heating of the elements.

Mounted in the lower end of the casing I is an insulating support 99carrying contact pins I09, WI and I02 which are insulated from eachother by the support 99. The pin I92 is connected to one of the coils ofthe actuator, and as when the plug 88 is plugged into the lower end ofthe casing I pin I02 is in the contact 91 this pin I02 is directlyconnected through the contact finger 92 with one side of the A. C.supply. Therefore the lead from pin I02 to the coil of the actuatorcorresponds with the lead 49 of the diagrams in Figs. 7 to 11. When theplug 88 is plugged into the lower end of the casing the pin I99 is incontact 81 and therefore the lead from this pin I09 to a coil in theactuator corresponds to the lead 58 between the rectifier 59 and the D.C. coils. Similarly the pin I9I is connected to the proper coils of theactuator and corresponds to the lead II. It will be seen that thisassembly makes an easily manipulated, simple and effective means forconnecting the rectifiers with the source of A. C. supply and alsoconnecting the rectifier and this source with the actuator in the propermanner, all that is necessary being to plug the plug 88 into the lowerend of the casing I and then insert the blades 83 and 92 of the plug 11into any standard outlet receptacle connection of a house wiring system.

Details of the contacts 81, 9| and 91 are shown in Figs. 18 and 19. Theycomprise hollow pins or sleeves I03 having a flange I04 adjacent one endto retain them in the casing 88 and to which the leads in the cable 86are connected. They are slit longitudinally as indicated at I05 so as togive yielding side walls to receive the pins I09, IM and I92 to give agood grip and electrical contact. The casing of plug 88 is made in twosections, only one of which is shown, and secured together by anysuitable means such for example as a screw or rivet I98.

It will be seen from Figs. 1, 2, 4 and 5 that the central pin IN issomewhat shorter than pins I99 and I02. This is to insure that pins I99and I02 will engage their contacts in plug 88 before pin I9I engages itscontact, so that should plug cap 11 be inserted in the outlet receptaclebefore plug 88 is inserted in the shaver the circuit will be closedthrough both rectiflers and the D. C. coils before power is applied andtherefore prevent both A. C. waves from passing through a singlerectifier.

The actuator may be mounted in the casing I by screws I91 passingthrough the laminated core and threaded into tapped metal members I98moulded in ribs or bosses l99 in one section, as sec ion 3 of thecasing. The free ends of the pole pieces I8, I9 and 29 may rest innotches in ribs II9 on the inner sides of the two sections 2 and 3 ofthe casing to steady the actuator and assist the screws I91. After theactuator is mounted in section 3, of the casing the other section 2 maybe placed over it and the sections secured together by any suitablemeans such as screws or rivets II (Figs, 1, 20 and 21) Having thus setforth the nature of my invention, what I claim is:

1 In a device of the character described, a reciprocating element, meansfor reciprocating the element comprising a magnetic core having spacedpoles, a reciprocable armature associated with said poles, means forexciting the poles to reciprocate the armature, a supporting element ofsubstantially U-shape having spring side arms and a connecting bar forsaid side arms, a stationary support, means for mounting the free endsof said arms on said stationary support, a supporting yoke having sidearms connected at one end to the armature and at the other end to theconnecting bar of the supporting element, and means for connecting saidlatter ends to the reciprocating element for operating it.

2. In a device of the character described, a reciprocating element,means for reciprocating the element comprising a magnetic core havingspaced poles, a reciprocable armature associated with said poles, meansfor altenately exciting the poles to reciprocate the armature, asupporting yoke having spaced side arms connected to the armature at oneend for carrying the armature, means extending between and connectingthe other ends of the side arms of the yoke and connected to thereciprocating element for operating it, and a' spring support for theyoke connected to the latter ends of said arms and adapted to yield topermit oscillating movements of the yoke with the armature and tendingto retain the armature in an intermediate position between the poles.

3. In a, device of the character described, a reciprocating element,means for reciprocating the element comprising a magnetic core havingthree spaced legs connected at one end, associated direct currentexciter coils and alternating current working coils mounted on the outerlegs for magnetizing these legs, a, movable armature associated with thefree ends of the legs and connected with the element for operating it,an insulating support at the other end of the casing, contacts mountedon said support connected with said coils, a plug insertable in saidcasing having contacts to engage said first mentioned contacts, a secondplug having projecting contact blades for insertion in an outletreceptacle to connect the plug with an alternating current supply, apair or rectifiers in said second plug with one of said blades connectedto the outlet side of one rectifier and the inlet side of the otherrectifier, and a cable having leads from the other sides of therectifier and the other blade contact to the contacts in the first plug,and each of said alternating current coils being wound in a sense toalternately increase or suppress the flux in the legs due to theassociated exciter coil during each cycle.

4. In a device of the character described, a reciprocating element,means for reciprocating said element comprising a magnetic core havingspaced poles, an armature adjacent said poles, means for magnetizing thepoles to reciprocate the armature, a yoke supporting the armature havingspaced side arms and a cross member connecting said arms, said armaturebeing at the opposite ends of the side arms from the cross member, aspring supporting member having resilient side arms and a memberconnecting said arms, a support, means for securing the side arms of thesupporting member to said support, means for mounting the cross memberof the yoke on the member connecting the arms of the supportin member,and means connecting said cross members with the reciprocating element.

5. In a device of the chaacter described, a reciprocating element, meansfor reciprocating said element comprising a magnetic core having spacedpoles, an armature adjacent said poles, means for magnetizing the polesto reciprocate the armature, a substantially U-shaped support havingresilient side arms and a cross member connecting said arms, meansconnecting the free ends of said arms to the core, a yoke mounted on thecross member of said support and having side arms carrying the armature,said armature being spaced from the connection of the yoke to the crossmember, and means connecting said cross member with the reciprocatingelement.

6. In a device of the character described, a reciprocating element,means for reciprocating said element comprising a magnetic core havingspaced poles, an armature adjacent said poles, means for magnetizing thepoles to reciprocate the armature, a substantially U-shaped supporthaving resilient side arms and a cross member, a supporting means, meansconnectin the free end portions of said arms to said supporting means, ayoke mounted on the cross member of said support and having side armscarrying said armature at a distance from the connection of the yoke tothe cross member, a spring connected 130 said cross member and extendingtransversely thereof and provided with laterally extending portionsresting on said supporting means, and means connecting said cross memberwith the reciprocating element for operating it.

'7. In a device of the character described, a reciprocating element,means for reciprocating said element comprising a magnetic coreconsisting of three spaced legs connected at one end, a reciprocatingarmature at the free ends, means connecting the armature to thereciprocating element, direct current exciter coils connected in aseries loop and alternating current working coils on the legs, means forconnecting the working coils in series with said loop and a singlesource of alternating current supply, a rectifier means in theconnection between one side of the supply and each of the exciter coilsto cause unidirectional current in said coils, and the working coilsbeing wound in a sense to alternately decrease or increase themagnetization of the direct current coils in the legs on each cycle.

8. In a device of the character described, a magnetic core having threespaced legs connected at one end, a reciprocating armature at the freeends, a direct current exciter coil and an associated alternatingcurrent working coil on each of the outer legs to magnetize said legs,means connecting the working coils in series with each other and asource of alternating current, means connecting each exciter coil withthe same source of supply and in series with the working coils but inparallel with each other, a rectifier in the connection between one sideof the supply and each of the exciter coils, one

exciter coil being connected to the outlet side of its rectifier and theother exciter coil being connected to the inlet side of its rectifier,and the working coils being wound in a sense to alternately change thedensity of the flux in the outer legs due to the associated excitercoils on each cycle.

9. In a device of the character described, a reciprocating element,means for reciprocating said element including a magnetic corecomprising independent magnetic circuits including spaced legs havingworking poles, a reciprocating armature at the pole ends of the core,means connecting the armature with .said element, D. C. exciter coils onthe legs of the core connected in a series loop and A. C. working coilson said legs, rectifier means for supplyi unidirectional current to theexciter coils, means for connecting the latter means and the workingcoils in series with the exciter coils and a single source ofalternating current supply, and said working coils being wound in asense to alter nately change the density of the flux produced by theexciter coils in the working poles during each cycle.

10. In a device of the character described, a reciprocating element,means for reciprocating said element comprising a magnetic core havingindependent magnetic circuits, a reciprocating armature at the polarextremities of said core, means connecting the armature to thereciprocating element, a direct current coil and alternating currentcoil on said core for excitation of each of said magnetic circuits, saidalternating current coils being connected in series and the directcurrent coils being connected in a series loop, means for connecting thesaid alternating current coils and said loop in series with a singlesource of alternating current supply, rectifier means in the connectionbetween one side of the supply and the direct current coils to causeunidirectional current in said coils, and said alternating current coilsbeing wound on the cores in a sense that during each cycle theyalternately change the density of the flux produced in the magneticcircuits by the direct current coils.

11. In a device of the character described, a reciprocating element,means is: reciprocating said element comprising a magnetic system havingcores forming independent magnetic circuits including magnetic poles, areciprocating armature at the poles of said magnetic system andconnected to said element. coacting direct current exciter coilsconnected in a series loop and alternating current working coilsconnected in series on the cores, and means connecting the alternatingcurrent coils and the loop in series with a single source of alternatingcurrent supply including rectifier means between said supply and thedirect current coils to cause unidirectional current in said coils, eachof said coils being wound in a sense that the working coil alternatelymodulate the flux of the exciter coils to reciprocate the armature.

12. In a device of the character described, a magnetic core comprisingindependent magnetic circuits including spaced legs having workingpoles, a reciprocating armature at the pole ends of the core, a D. C.exciter coil and an A. C. working coil on a core leg of each magneticcircuit, means connecting the working coils in series with each of theexciter coils and the exciter coils in a series loop, means connectingthe opposite ends of the exciter coils from those connected with theworking coils to one side of a source of alternating current supply, arectifier means between said connection and each exciter coil and saidconnection being to the inlet side of one rectifier means and the outletside of the other rectifier means to 'ause unidirectional current toflow in the excite'r coils, said working coils being wound in a sense toalternately change the density of, the flux produced by the excitercoils in the working poles during each cycle, and means connecting theworking coils with the other side of the source of supply.

13. In a device of the character described, a

magnetic core having independent magnetic circuits, a reciprocatingarmature at the polar extremities of said core, a direct current coiland an alternating current coil for exciting each magnetic circuit, saidalternating current coils being connected in series with eachother andwith each direct current coil, said direct current coils being connectedin a series loop, means connecting the alternating current coils withone side of a source of alternating current and means connecting theother side of said supply to the opposite ends of the direct currentcoils from their connection to the alternating current coils including arectifier means between said supply and each coil arranged with thesupply connected to the inlet side of onerectifler means and the outletside of the other rectifier means. and said alternating current coilsbeing wound in a sense that during each cycle they alternately increaseor decrease the flux produced in the magnetic circuits by the directcurrent coils.

14. In a device of the character described, a reciprocating element,means for reciprocating said element comprising a magnetic systemincluding a magnetic core having spaced legs forming magnetic poles, areciprocating armature adjacent said poles for operation thereby,associated exciting coils connected" in a series loop and workingcoilson legs of the core, means for connecting said working coils inseries with said loop and a single source of alternating current supply,rectifier means between said supply and the exciting coils to causeunidirectional current in said coils, and said working coils being woundin a sense with respect to the exciting coils that the working coilsalternately modulate the flux in the legs due to the exciting coilsduring each cycle.

15. In a device of the character described, a reciprocating element,means for reciprocating said element comprising a magnetic core havingthree spaced legs connected at one end and forming magnetic poles attheir other ends, a reciprocating armature at the pole ends connected tosaid element, an associated exciter coil and a working coil on each ofthe outer legs, said exciter coils being connected in a series loop, andmeans connecting the working coils in series with the loop and a singlesource of alternating current supply, rectifier means between saidsupply and the exciter coils to cause unidirectional current in saidcoils each of said working coils being wound in a sense with re spect toits associated exciter coil that the working coils alternately changethe density of the flux of the exciter coils in the outer legs toreciprocate the armature.

THOMAS J. MURPHY.

